correct permission of cassandra-rackdc.properties
correct permission of cassandra-rackdc.properties

Signed-off-by: Takuya ASADA <4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>

scylladb/scylla,raphaelsc/scylla,raphaelsc/scylla,avikivity/scylla,kjniemi/scylla,duarten/scylla,scylladb/scylla,kjniemi/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,duarten/scylla,raphaelsc/scylla,kjniemi/scylla